1. Field of the Invention:
This invention pertains to motor drive speed control systems. Specifically it pertains to gyro motors using reference coils in place of saturable reactors for motor start up and spin direction.
2. Description of the Prior Art:
Saturable reactors in previous motor drives determined the position of the magnet for application of two phase drive signals during start up and running. Reference coils can only do this if the magnet is in motion. When both sets of reference coils are used independently, the gyro is capable of spinning in either direction with equal preference.
Saturable reactors require matched sets of four with close tolerances for proper operation. Elimination of saturable reactors both reduces cost and eases the burden of construction required by their use.